Genetics and Evolution Unit Test Review

Genetics and Evolution Unit Test Review Flashcards

What are four key reasons cells divide?

Cell division, cell repair/healing, cell growth, cell reproduction

What occurs during the Cell Growth (G1) phase of Interphase?

Cell increases in volume and size

What occurs during the S phase of Interphase?

DNA replication

What occurs during the G2 phase of Interphase?

Preparation for mitosis

What are the main activities of cells during interphase?

Obtaining energy, synthesizing products, repairing damage, and fighting disease

What events characterize Prophase?

Chromatin condenses into visible chromosomes, nuclear membrane breaks down, and spindle fibres begin to form

What happens during Metaphase?

Spindle fibres line the chromosomes in the center of the cell

What occurs during Anaphase?

Spindle fibres pull sister chromatids apart to opposite poles, ensuring each new cell gets an identical set of chromosomes

What happens during Telophase?

A new nuclear membrane forms around each set of chromosomes, creating two distinct nuclei

What happens during Cytokinesis?

The cytoplasm divides, and the cell splits into two daughter cells

What are the components of a nucleotide?

Sugar, nitrogenous bases, and a phosphate group

What is Chromatin?

Uncondensed DNA (Interphase)

What is a Chromatid?

One of the two halves of a chromosome (PMAT)

What are Chromosomes?

Condensed structures containing genetic information (PMAT)

What are Homologous Chromosomes?

Pairs of chromosomes, one from each parent, with similar shape, size, and genes but different alleles

What are Autosomes in somatic cells?

Chromosome pairs 1-22

What are Sex Chromosomes?

The X and Y chromosomes

What is the chromosome composition of somatic cells and gametes in humans?

Somatic cells (46 chromosomes- diploid, 2n=46) contain 44 autosomes and 2 sex chromosomes, while gametes (23 chromosomes- Haploid, n=23) contain 22 autosomes and 1 sex chromosome

What is Synapsis during Prophase I?

Homologous chromosomes find each other and pair up to form a tetrad

What is Crossing Over?

Homologous chromosomes swap pieces of DNA, resulting in genetic recombination

What is a Tetrad?

A pair of homologous chromosomes

What occurs during Independent Assortment in Metaphase I?

The order the tetrad lines up is random

What happens during Anaphase I?

Spindle fibres rip apart homologous chromosomes, although sister chromatids are still attached and the cell transitions from diploid to haploid

What is the result of oogenesis?

Meiotic divisions result in unequal distribution of cytoplasm with the 4 daughter cells, resulting in 1 viable egg cell and 3 polar bodies (n chromosomes)

What is spermatogenesis?

Meiotic divisions result in 4 daughter cells of equal size and 4 sperm cells (n chromosomes)

What information can be determined from karyotypes?

Number of chromosomes, sex chromosomes, abnormalities

What is Monosomy?

1 chromosome from a pair is missing

What is Trisomy?

An extra chromosome in a pair

What is Phenotype?

Physical traits that are shown

What is Genotype?

The combination of alleles

What is Homozygous?

An organism that has the same alleles (BB or bb)

What is Heterozygous?

An organism that has different alleles (Bb)

What is genetic Complete Dominance?

When the dominant allele completely hides the recessive allele in heterozygous individuals

What is genetic Incomplete Dominance?

A mix between both alleles

What is Microevolution?

Change in a specie

What is Gene Flow (Migration)?

The movement of alleles from one population to another

What is Non-Random Mating?

Mating among individuals where one organism chooses who to mate with based on a physical trait

What is Genetic Drift?

A change in allele frequencies based on chance events

What is Biogeography?

The distribution of species across different geographic locations and how they change over time

What are Homologous structures?

Similar structure but different function

What are Analogous structures?

Different structure but same function

What is Embryology?

DNA is a species whose embryos resemble each other may have shared a common ancestor

What is Prezygotic?

The Barrier that prevents mating between species and prevents fertilization of the eggs

What is Postzygotic?

The Barrier that prevents hybrid zygotes from developing into fertile individuals

What is Deforestation?

Large areas of forests are cut down or burned

What is Overfishing?

Too many fish are caught too quickly, and the fish populations can't recover.

What is Species?

A group of organisms that can interbreed and produce fertile offspring under natural conditions

How are viruses classified?

Genetic Makeup, Morphology, Mode of replication

What is the difference between a Lytic and Lysogenic Cycle?

Lytic has Shorter incubation period and the Lysogenic cycle has a Longer incubation period

Name 4 types of Archaea Environments

Halophile, Thermophile, Acidophile, Methanogens