Bio unit 7 quiz

Males only have

One copy of the x chromosome

In sex linked traits males are more likely to

obtain a recessive alleles if its present In the traits

Meiosis doesn’t make body cells it makes sperm and egg cells otherwise known as what

gametes

Gamtetes

haploid repoductive cells (sex cells) that unite during sexually repoduction to form a diploid zygote

Human sperm cells and egg cells have

46 chromosomes

How we count chromosomes

By the number of centromeres present

In gamete, when the 46 chromosomes duplicate, we still say there are how many chromosomes

46

In meiosis your going to divide twice and therefore do “PMAT”

Twice

What PMAT stands for

Prophase, metaphase, anaphase, and telophase

Homozygous

Chromosomes are approximately the same size, contraon the same types of genes, in the same locations

Crossing over

When chromosomes pair up and exchange some information giving us “recombinant chromosomes”

After PMAT 1 (and cytokinesis) what happens next

Miosis 2 AKA, prophase 2

Becuase of independent assortment and crossing over , the products of meiosis will have…

Variety

Anaphase 1

Homozygous chromosomes are seperated and pulled to opposite poles. Sister chromatids remain together

Telophase 1

Nuclear membrane reforms, spindle fibers fall apart. Cytoplasm will divide (“cytokinesis”)

Telophase 1 results in

two separate cells. Each cell has 23 chromosomes and 46 chromatids.

Prophase II

Nuclear membrane breaks down, centrioles move to the poles, spindle fibers form. Chromosomes done condense (already condensed from meiosis 1).

Metaphase II

Spindle fibers attach to centromers. 2 total sister chromatids

Anaphase II

Sister chromatids are pulled to opposite sides of the cell

Telophase II

Nuclear envolope forms, chrososomes decondense, spindle fibers fall apart. Cytoplasm divides (“cytokinesis”)

Purpose of meiosis is a type of what

cell division

Meiosis goes from what

1 diploid cell to 4 haploid cells (gametes)

Homologous Pairs

Homologous chromosomes are spit during meiosis I

Sister chromatids are spit during

meiosis I

Sister chromatids are split during

meiosis II

Meiosis I: Phrophase I

Nuclear membrane breaks down, spindle fibers form, centrioles move to the poles. Chromosomes finish condensing. Homoologous chromosomes pair up. Variety comes from “crossing over”

Metaphase I

Homolougous chromosomes pair up across the middle of the cell

Metaphase I happens

randomly (mother Vs. Father)

Metaphase I is called

Independent assortment, provides variety.

Spindle fibers attach to centromeres during what phase

Metaphase I

Each pair of chromosomes is called

homologous pair

Each pair of chromosomes have the same

Length, General appearance, and same genes in the same order.

The two copies of each pair of chromosomes may be

Different between the two chromosomes

Autosomes make up how many pairs

1-22

Autosomes contain genes for

Characteristics thats not directly related to the sex of an organim

Sex chromosomes include

X and Y chromosomes in humans.

Female

Two X chromosomes (XX)

Male

X and Y chromosomes (XY)

Sex chromosomes match up to form the

23rd pair of chromosomes