Test 4 Constructed Response

What is apoptosis?

programmed cell death

Why is apoptosis important?

Eliminates excess cells, creates structures, and weeds out aging and defective cells

Mitosis

Cell Division, Makes exact copies, somatic cells, 2n Diploid in humans 23 pairs, Growth, maintenance, repair and asexual reproduction

Meiosis

What are the three steps for interphase (Mitosis)?

• G_1- Cell growth, Organelle duplication

• Synthesis- DNA is replicated

• G_2- Preparation for mitosis

What are the three steps for interphase (Meosis I)?

Some cells, brain cells and nerve cells for example, never replicate. What stage are they permanently stuck in? 

G0 Non Dividing

In interphase, when DNA is replicating itself, what is the name of the enzyme that separates the DNA double helix?

Helicase

What is the name of the enzyme used to rejoin the separated strands of DNA? 

Ligase

Name the structure that joins two sister chromatids together?

Centromere

Kinetochores are proteins that attach to the centromere and allow for the attachment of spindle fibers to the sister chromatids. During what phase of mitosis or meiosis does this attachment occur?

Prophase

Name two ways a healthy cell keeps uncontrolled cell growth from occurring?

1. Growth factors- Proteins that control cell replication

2. Checkpoints

Cancer can be caused by environmental factors as well as inherited genetically. We discussed two genes that, if mutated, can cause cancer. What are they?

During metaphase of mitosis sister chromatids line up. During metaphase I of meiosis tetrads/homologous chromosomes line up. What is the difference between sister chromatids and tetrads?

What are the two methods that lead to genetic diversity in gametes during meiosis? During what phases do they occur?

What is polyploidy?

Can humans survive the error of Polyploidy?

Can plants survive the error of Polyploidy?

Trisomy 21, or any other disorder beginning with trisomy, is caused by what?

If red feathers (R) are dominant over blue feathers in parrots, what are the two possible genotypes for a red parrot? What is the one possible genotype for a blue parrot?

Red Parrot- RR, Rr

Blue Parrot- rr

If red (R) is incompletely dominant over blue feathers in parrots what is the one genotype for red parrots? The one genotype for blue parrots? And what is the one genotype for purple parrots?

If long tails (L) in jaguars and big spots (B) are dominant over short (l) and small (b), what is the phenotypic ratio of a heterozygous parent crossed with a homozygous recessive parent? 

What is Mendel’s 2^nd Law?

An example of Mendel’s 2nd law

Why are X linked disorders more common than Y linked disorders?

Why is it more common for men to express X linked disorders?

If male pattern baldness is an X linked gene and is the recessive trait, cross a woman who is homozygous recessive with a man who carries the dominant allele. What are the chances they will have a son with male pattern baldness?