Cell Biology Chapter

17 Questions

In the context of R-selection and K-selection, species that produce numerous offspring and have a high population growth rate are typically classified as:

R-selected species

Which of the following best describes a commensalistic relationship between species?

One species benefits, and the other is unaffected

In the logistic population growth model, what happens as a population approaches its carrying capacity?

The growth rate decreases

During primary succession, the initial stage is often characterized by the presence of:

Lichens and mosses

Eutrophication in aquatic systems is primarily caused by an excess of:

Nitrogen and phosphorus

During which stage of meiosis does crossing over occur?

Prophase I

How do cell checkpoints prevent cancer from developing in most cells?

By repairing DNA damage, promoting apoptosis, and halting the cell cycle until errors are corrected

Which two types of cancer treatments identify cells based on location?

Radiation therapy and surgery

What is the ploidy level of cells at the end of meiosis I?

Haploid (n)

In what way do sexually-reproducing organisms create genetic variation in their offspring?

Recombination, independent assortment, and random fertilization

Why might cicadas have evolved periodicity in their life cycle?

To avoid predation and environmental changes

Which component of the chromosome is primarily involved in the condensation of DNA?

Histone

What role does the G1 checkpoint play in the cell cycle?

It checks for cell size, nutrients, and DNA integrity.

How do spindle fibers contribute to mitosis?

They segregate chromosomes during cell division.

What genetic relationship exists between a parent cell and a daughter cell produced by mitosis?

Both daughter cells are genetically identical to the parent cell.

What characterizes a sex-linked trait?

It is associated with genes located on sex chromosomes.

What is the diploid number for humans, and what does it signify?

46; the total number of chromosomes in a human somatic cell

Study Notes

Cell Biology

Chromosome is a thread-like structure made up of chromatin
Chromatid is a replicated chromosome that is connected to its sister chromatid at the centromere
Chromatin is a complex of DNA, histone proteins, and non-histone proteins
Centromere is the region where the sister chromatids are connected
Telomere is the region at the end of a chromosome
Histone is a protein that DNA wraps around to form chromatin
Homologous chromosomes are pairs of chromosomes that have the same genes and are similar in structure
Autosome is a non-sex chromosome
Sex-linked trait is a characteristic that is influenced by genes on the sex chromosomes

Mitosis

Mitosis is the process of cell division that results in two daughter cells with the same number of chromosomes as the parent cell
Centriole is a structure that helps to organize the spindle fibers during mitosis
Parent cell is the original cell that divides into two daughter cells
Daughter cell is the resulting cell from mitosis
Somatic cell is a non-reproductive cell that undergoes mitosis
Cell division checkpoint is a mechanism that ensures the cell is ready to divide
Spindle fibers are structures that separate the chromosomes during mitosis
Spindle fibers perform the following tasks: separate chromosomes, align them at the center, and move them to the poles
Mitosis results in two daughter cells with identical genetic material
Daughter cells are genetically identical to each other and to the parent cell

Cancer

Cancer is a disease characterized by uncontrolled cell growth and division
Metastasize is when cancer cells spread to other parts of the body
Tumor is a mass of abnormal cells
Apoptosis is programmed cell death, which is a normal process that prevents cancer
Oncogene is a gene that has the potential to cause cancer
Proto-oncogene is a normal gene that can become an oncogene if mutated
Cancer cells have characteristics such as uncontrolled growth, immortality, and invasive behavior
Cell checkpoints can prevent cancer by stopping the cell cycle when DNA is damaged

Genetics and Ecology

Cancer & Genetics

Cancer is caused by genetic mutations that disrupt normal cell division and growth
Cancer is related to genetics because genetic mutations can lead to cancer
Cell checkpoints can prevent cancer by stopping the cell cycle when DNA is damaged
There are four types of cancer treatments: surgery, radiation, chemotherapy, and targeted therapy
Two types of cancer treatments identify cells based on location: surgery and radiation

Meiosis

Meiosis is the process of cell division that results in four daughter cells with half the number of chromosomes as the parent cell
Recombination or crossing over occurs in prophase I of meiosis
Independent assortment occurs in metaphase I and II of meiosis
Gamete is a reproductive cell that has undergone meiosis
Zygote is the cell that results from the fusion of two gametes
Meiosis creates genetic variation in offspring through crossing over, independent assortment, and random fertilization
Four daughter cells are created in meiosis, each with unique genetic material
Daughter cells are genetically unique to each other and to the parent cell

Genetics

Patterns of inheritance include sex-linked, autosomal dominant, autosomal recessive, and sex-influenced
Pedigrees can be used to identify patterns of inheritance
Punnett squares can be used to model monohybrid and dihybrid crosses

Ecology

Cicadas

Periodicity is the long-term cycle of cicada populations
Cicadas have evolved periodicity to avoid predators and ensure reproduction
Cicadas spend 13-17 years underground, 4-6 weeks above ground, and 1-2 months as adults

Lesson 2: Community Ecology

R-selection and K-selection are two strategies for population growth
Types of interspecies relationships include predator-prey, mutualism, and commensalism
Population curves can be logistic or exponential
Carrying capacity is the maximum population size that an environment can support
Succession is the process of community change over time
There are three stages of succession: initial, intermediate, and complex community

Lesson 3: Biogeochemical Cycles

Carbon cycle involves the movement of carbon between the atmosphere, oceans, and land
Carbon sinks are areas where carbon is stored, such as oceans and forests
Carbon sources are areas where carbon is released, such as fossil fuels and volcanic eruptions
Global warming is caused by an increase in carbon dioxide in the atmosphere
Nitrogen cycle involves the movement of nitrogen between the atmosphere, oceans, and land
Nitrogen fixation is the process of converting atmospheric nitrogen into a usable form
Eutrophication is the process of excess nutrients in an ecosystem, leading to algae growth and oxygen depletion

Test your knowledge of cell biology with this quiz on chromosomes, histones, and more! Learn about the structures and functions of cellular components and their roles in mitosis.

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