Biology Quiz on Gametes and Autogamy

Gametes are reproductive cells (like sperm and egg) that combine to form a zygote. Most organisms produce different types of gametes - one larger and one smaller, making them heterogametes.

Autogamy is a type of self-fertilization where the pollen from the anther of a flower pollinates the stigma of the same flower.

Isogametes are gametes (sex cells) of the same size and morphology (structure). They are identical in appearance.

Homogametes are gametes (sex cells) that are similar in size and appearance. They are identical in terms of size and morphology.

Hemigametes are gametes (sex cells) that are half the size of the original cell. They have half the number of chromosomes. They are formed through meiosis during sexual reproduction.

Pollination occurs when pollen grains are transferred from the anther of a flower to the stigma of another flower of the same species. It's a critical step in sexual reproduction of flowering plants.

Maturation of anther and stigma at different times prevents self-pollination. It is often seen as a mechanism to promote cross-pollination by ensuring that pollen from one flower will be transferred by an external agent (like wind or insects) to the stigma of another flower. This promotes genetic diversity.

Dehiscence of anther is the process where the anther splits open to release pollen grains. It's the mechanism that allows flowers to release pollen for pollination.

Activated sludge is a type of wastewater treatment where microorganisms are used to break down organic matter in the wastewater. The sludge should settle quickly to allow for efficient separation and removal of the treated water.

AIDS (Acquired Immunodeficiency Syndrome) is a chronic, potentially life-threatening condition caused by the human immunodeficiency virus (HIV). It weakens the immune system by destroying important cells that fight infection.

Recombinant DNA technology involves inserting a desired gene into a vector, typically a bacterial plasmid. The vector then delivers the gene into a host cell, where it can be expressed to produce the desired protein.

Organisms can be classified into two main categories based on their ability to regulate their internal environment: conformers and regulators.

An antibiotic resistance gene is a marker gene used in genetic engineering to identify cells that have successfully incorporated the recombinant DNA. It allows scientists to distinguish between transformed cells and those that haven't taken up the new DNA.

Fish mortality in a lake can be caused by a variety of factors, including water pollution, habitat destruction, and disease outbreaks.

The process of transporting materials across cell membranes is essential for cell function and communication.

The scientific method is a systematic approach to acquiring knowledge by observation, experimentation, and analysis.

A phenomenon where excessive use of fertilizers (like urea and phosphates) and pesticides (like DDT) leads to an imbalance in the lake ecosystem. It results in a decrease in phytoplankton population (the basis of the food chain) due to algal blooms, followed by a decline in oxygen levels and fish mortality.

This type of pedigree chart indicates an autosomal recessive inheritance pattern. The trait is masked in the parents, meaning they are carriers, but appears in the offspring.

Sterilization techniques (like vasectomy or tubectomy) are permanent methods and require surgery. They are highly effective for the long term but are irreversible. Therefore, couples often prefer to explore other temporary contraceptive methods first.

Haploid organisms have only one set of chromosomes. In these organisms, mitosis produces gametes that also have only one set of chromosomes. While meiosis is not needed for gamete production, it plays a critical role in sexual reproduction for organisms with diploid cells.

The placenta acts as a vital interface between the fetus and the mother's body. Its functions include supplying nutrients and oxygen from the mother's blood to the fetus and removing waste products from the fetus to the mother's blood.

Sticky ends are short sequences of unpaired nucleotides that are formed when a restriction enzyme cuts DNA at specific recognition sites. They are called 'sticky' because they can easily bind with complementary sticky ends from another DNA fragment.

Most mammalian cells only transcribe a small portion of their genetic information into functional RNA. This is because not all genes are needed for every cell type and function. Transcription is tightly regulated to ensure only necessary proteins are produced.

The thymus gland is responsible for producing T-cells, a crucial component of the immune system. Removing it would significantly impair the body's ability to fight infections due to a lack of mature T-cells, weakening the immune response.

A condition in which a person's blood doesn't clot properly, leading to excessive bleeding. It's caused by a deficiency in clotting factors.

The genetic makeup of an individual, represented by symbols like XX or XY for sex chromosomes.

A trait like flower color can have multiple forms (violet or white) due to different versions of the gene. Some traits, like skin color, show a wide range of variation due to multiple genes interacting.

Cells must have the correct number of chromosomes for proper growth and development. Errors often lead to problems.

A specialized cell in plants that is involved in sexual reproduction, containing half the number of chromosomes found in other cells.

The fusion of two gametes (sperm and egg) to form a single cell, the zygote, which starts the development of a new organism.

The process of releasing a mature egg cell from the ovary.

The process of carrying a developing embryo inside the uterus, starting from the moment of fertilization.

A situation where a single gene mutation leads to different phenotypes depending on whether the individual is homozygous or heterozygous for the mutation.

A genetic condition where an individual inherits two copies of a mutated allele, leading to the full expression of the disease.

A genetic condition where an individual inherits one copy of a mutated allele and one copy of a normal allele, resulting in a milder form of the disease or no symptoms.

A genetic condition where a mutation in a gene affects the ability to perceive certain colors, particularly red and green.

CNG (Compressed Natural Gas) is a cleaner alternative to gasoline and diesel fuel for vehicles. It significantly reduces emissions of harmful pollutants like carbon monoxide, particulate matter, and hydrocarbons. EURO norms are emission standards that set limits on the amount of pollutants that vehicles can emit. By complying with EURO norms, vehicles become more environmentally friendly. Emission regulations are government-imposed rules that control the release of pollutants from vehicles. These regulations aim to improve air quality by ensuring that vehicles meet specific emission standards.

The introduction of CNG as an alternative fuel source in Delhi and other Indian cities has led to a significant reduction in vehicular air pollution. CNG emits fewer pollutants compared to traditional fuels like gasoline and diesel, resulting in cleaner air. The implementation of EURO norms has also been effective in lowering emissions by setting tighter emission limits for vehicles. These regulations have encouraged automakers to produce vehicles with improved emission control technologies, further contributing to cleaner air.

Anthropogenic actions, such as habitat destruction, pollution, and climate change, are rapidly altering the environment. This rapid change puts pressure on species to adapt, leading to evolution happening on a much shorter timescale than the traditional millions of years. For example, a population of insects might evolve resistance to a new pesticide in just a few years due to the selective pressure imposed by the pesticide. This accelerated evolution can be both beneficial and detrimental. While some species might adapt and thrive, others may struggle to keep up with the rapid changes and face extinction.

An ecological pyramid is a graphical representation of the energy flow in an ecosystem. It shows the relative amounts of organisms at each trophic level. The base of the pyramid represents the producers (plants), which have the largest biomass and energy content. The apex of the pyramid represents the top predators, which have the smallest biomass and energy content. This pyramid is called a pyramid of biomass because it depicts the relative amounts of biomass at each trophic level.

A pyramid of numbers is a type of ecological pyramid that shows the relative number of organisms at each trophic level. For example, a forest ecosystem might have a pyramid of numbers where the base represents a large number of plants, followed by fewer herbivores, and even fewer carnivores at the apex. A pyramid of biomass is a type of ecological pyramid that shows the amount of biomass at each trophic level. In an aquatic ecosystem, the pyramid of biomass can be inverted because the producers (phytoplankton) may have a lower biomass than the primary consumers (zooplankton).

The molecule 'X' synthesized by the 'i' gene is a repressor protein. The repressor protein is inactivated by the presence of lactose. Specifically, lactose binds to the repressor protein, changing its shape and preventing it from binding to the operator region of the lac operon. This process allows the transcription of the lac operon genes, including the gene for β-galactosidase.

The structural gene that codes for β-galactosidase is called 'lacZ'. It is one of the three structural genes in the lac operon, along with 'lacY' and 'lacA'. β-galactosidase is an enzyme that breaks down lactose into glucose and galactose.

The transcription of the lac operon is stopped when lactose is absent. The repressor protein binds to the operator region of the lac operon, blocking RNA polymerase from initiating transcription. This occurs because lactose is the inducer molecule that inactivated the repressor. In the absence of lactose, the repressor remains active, preventing transcription.