Biology Grade 11 Genetics Overview

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Questions and Answers

What is the outcome of gametogenesis in males?

Creation of multiple egg cells over a lifetime

Production of one ovum each month

Constant production of about 200 million sperm per day (correct)

Formation of polar bodies during meiosis

Which base pairing is NOT correct as per DNA structure?

Thymine pairs with Adenine

Cytosine pairs with Adenine (correct)

Adenine pairs with Thymine

Guanine pairs with Cytosine

During which phase does crossing over occur, enhancing genetic diversity?

Prophase I (correct)

Telophase II

Metaphase II

Anaphase I

What characteristic distinguishes homologous chromosomes from each other?

They contain different alleles of the same genes (C) Signup and view all the answers

What occurs during nondisjunction in meiosis?

Homologous chromosomes move to the same pole during anaphase I (A) Signup and view all the answers

How many total gametes can a female realistically produce through oogenesis over a lifetime?

A few hundred eggs (C) Signup and view all the answers

What is the primary role of independent assortment during gamete formation?

Random segregation of maternal and paternal chromosomes (C) Signup and view all the answers

Which of the following structures is responsible for transporting chewed food from the mouth to the stomach?

Esophagus (C) Signup and view all the answers

Which of the following enzymes is NOT produced by the pancreas?

Lactase (B) Signup and view all the answers

Which of the following statements about the large intestine is INCORRECT?

It is where the majority of nutrient absorption occurs. (C) Signup and view all the answers

Which of the following is a CORRECT pairing of a type of fungus and its role in society?

Aspergillus - Used in production of cheese and soy sauce (B) Signup and view all the answers

Which of the following fungal structures is MOST analogous to the roots of a plant?

Mycelium (A) Signup and view all the answers

What characteristic distinguishes methanogens from other organisms?

They generate methane as a metabolic byproduct. (A) Signup and view all the answers

Which statement correctly describes the reproductive capabilities of Animalia?

They mainly produce sexually in both aquatic and terrestrial environments. (D) Signup and view all the answers

In which scenario would a virus leave the lysogenic cycle?

When an environmental change triggers it. (A) Signup and view all the answers

What type of organisms are classified under Fungi?

Multicellular eukaryotes with a cell wall, like mushrooms. (A) Signup and view all the answers

Which of the following statements is true about viruses?

They are considered non-living infectious agents. (D) Signup and view all the answers

Which process occurs first during the lytic cycle of viral replication?

Attachment of the virus to the host cell. (D) Signup and view all the answers

How do methanogens primarily differ from members of the Plantae kingdom?

Methanogens are primarily unicellular, whereas Plantae are multicellular. (D) Signup and view all the answers

What describes the dormancy phase in the lysogenic cycle?

The viral DNA is incorporated into the host DNA without replication. (B) Signup and view all the answers

In terms of cellular organization, which of the following groups is entirely eukaryotic?

Animalia, Plantae, and Fungi. (B) Signup and view all the answers

What is a characteristic feature of organisms in the Protista kingdom?

They can be both unicellular and multicellular. (C) Signup and view all the answers

Which of the following scenarios BEST describes the founder effect?

A small group of birds migrates to a new island and establishes a new population, which has a limited genetic diversity compared to the original population. (C) Signup and view all the answers

Which of the following is an example of a postzygotic isolating mechanism?

A hybrid offspring of two different species of frogs is unable to reproduce. (D) Signup and view all the answers

Which statement BEST explains the impact of the bottleneck effect on a population's genetic diversity?

The bottleneck effect reduces genetic diversity, making the population more vulnerable to environmental changes. (C) Signup and view all the answers

Which of the following is NOT a type of prezygotic isolating mechanism?

Hybrid sterility (C) Signup and view all the answers

Which of the following scenarios MOST LIKELY results in a founder effect?

A group of humans moves to a new island and establishes a new population. (D) Signup and view all the answers

Which of the following is NOT a key factor in determining a species' taxonomic classification?

Habitat (C) Signup and view all the answers

Which of the following statements CORRECTLY describes the relationship between genetic drift and population size?

Genetic drift is more pronounced in small populations because random events have a greater impact on allele frequencies. (A) Signup and view all the answers

Which of the following is an example of a mechanical isolation mechanism?

Two species of insects have different physical structures that prevent them from mating successfully. (C) Signup and view all the answers

Which of the following statements BEST describes the role of reproductive isolation in speciation?

Reproductive isolation is a factor that prevents gene flow between populations, leading to the development of new species. (D) Signup and view all the answers

Which of the following characteristics is a feature common to both prokaryotic and eukaryotic cells?

Presence of ribosomes (A) Signup and view all the answers

Which of the following statements is TRUE about eukaryotic cells?

They evolved before prokaryotic cells. (D) Signup and view all the answers

Which species concept relies on the ability of two organisms to produce fertile offspring under natural conditions?

Biological Species Concept (C) Signup and view all the answers

What is a significant drawback of the Morphological Species Concept?

It fails to consider variations within a population and can lead to misclassification. (B) Signup and view all the answers

What is the primary reason why the Biological Species Concept cannot be applied to all organisms?

It cannot be applied to extinct organisms or organisms that reproduce asexually. (B) Signup and view all the answers

Which of the following is a key characteristic of the Biological Species Concept?

Interbreeding and fertile offspring under natural conditions. (A) Signup and view all the answers

Which of the following is NOT a disadvantage of the Morphological Species Concept?

Limited applicability to organisms with complex life cycles. (B) Signup and view all the answers

What is the primary distinction between prokaryotic and eukaryotic cells?

Eukaryotic cells have a membrane-bound nucleus. (C) Signup and view all the answers

Which of the following is an accurate statement about the Biological Species Concept?

It defines species based on the ability to interbreed and produce fertile offspring. (C) Signup and view all the answers

What is the main reason why the Morphological Species Concept is the most widely used, despite its limitations?

It is the simplest and easiest to apply. (A) Signup and view all the answers

Study Notes

Biology Grade 11 Exam Notes

Terms:
- Somatic cells: body cells
- Alleles: different forms of the same gene
- Cellular respiration: allows organisms to use energy stored in food to form ATP molecules
Unit 1: Genetics
- Meiosis and mitosis are covered in the notebook notes.
- DNA Structure:
  - DNA is a double helix (twisted ladder).
  - Each unit along the strand is a nucleotide composed of a phosphate group, a sugar group, and a base.
  - Base pairings: A-T, G-C.
  - Complementary base pairs allow each strand of DNA to serve as a template for DNA replication.
- DNA Replication:
  - Replication consists of two identical strands (sister chromatids).
  - Homologous chromosomes: Humans have 46 chromosomes, two in each pair. Similar genes but not identical.
- Autosomes & Sex chromosomes:
  - Autosomes: Non-sex chromosomes.
  - Males have XY, females have XX.
- Gametogenesis:
  - Production of sex cells.
  - Oogenesis: Occurs in ovaries, produces one egg cell per month (few hundred over lifetime).
  - Spermatogenesis: Occurs in testes, produces sperm cells constantly (about 200 million per day).
- Multiple Births:
  - More than one egg released, both fertilized by different sperm (fraternal).
  - One egg, fertilized by one sperm, that later divides(identical).
- Independent Assortment: Chromosome pairs randomly assort in metaphase I forming different combinations of maternal and paternal chromosomes in gametes.
- Crossing Over: During prophase I, homologous chromosome pairs exchange genetic material, resulting in recombinant chromosomes with mixed traits.
- Nondisjunction: Occurs during anaphase I when two homologous chromosomes or sister chromatids fail to separate, resulting in a daughter cell missing a chromosome or having an extra chromosome

Unit 2: Evolution

Evolution: The process of significant genetic changes in a species or population over time.
Sources of Evidence:
- Fossils: Footprints, petrified remains, casts, imprints, amber, ice preservation. Fossil record is often incomplete.
  - Examples: Archeopteryx (characteristics of both reptiles and birds), Tiktaalik (possible evolutionary transition from fish to amphibian), Cambrian explosion (sudden appearance of diverse animal life). Fossil record has limitations due to gaps in the fossil record and evidence destruction.
- Geographical Distribution: Closely related species tend to be found in geographically close areas. Island species are more closely related to mainland species than to species in distant areas.
- Homologous Structures: Species with similar structures but different functions, indicating a common ancestor. Eg. forelimbs (whales, birds, humans).
- Comparative Embryology: Similarities in the development of embryos suggest distant, common ancestors.
- Biochemical Similarities: Similarity in molecular structures (universal genetic code) and cell components among organisms suggests shared ancestry.
Results in Daughter Cells missing a chromosome or having an extra chromosome due to mutations (like errors in crossing-over, duplications, inversions, translocations).

Unit 3: Diversity of Life

Taxonomy: Classification system (Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species).
Dichotomous Key: A tool for identifying organisms based on a series of yes/no questions.
Prokaryotes vs. Eukaryotic cells: Difference between cell types, structure, reproduction, organelle presence.

Unit 4: Animal Systems

Digestive System: Organs that chemically break down food for use by the body.
- Mouth: Chewing, Salivary enzymes.
- Esophagus: Transports food.
- Stomach: Digests proteins.
- Small Intestine: Final digestion and absorption of nutrients.
- Large Intestine: Water absorption.
Respiratory System: Moves air into and out of the lungs for gas exchange.
- Nose: Initial intake of air.
- Trachea: Transports air to the lungs.
- Lungs: Gas exchange.
Circulatory System: Transports materials throughout the body.
- Heart: Pumps blood.
- Blood vessels: Arteries, veins, capillaries.

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Description

Test your knowledge on key genetics concepts from Biology Grade 11. This quiz covers crucial terms such as DNA structure, meiosis, mitosis, and the concepts of alleles and gametogenesis. Prepare to demonstrate your understanding of how these processes define heredity and cellular functions.