CHAPTER 10

Human body cells are diploid meaning they have _____ chromosomes.

46

Gametes are haploid which means they have _____ chromosomes.

23

If a person is homozygous for a particular allele, that means they have _____.

two identical copies

Which of the following could be passed on to future generations?

a mutation in an egg cell resulting in too many chromosomes

The end result of mitosis is _____.

two identical cells

The end result of meiosis is _____.

four different cells

Which structure implants in the endometrium?

blastocyst

If the umbilical vein is carrying blood to the fetus, it has oxygen in it so it is a red vein.

true

What is gastrulation?

differentiation of the three main germ layers

Down syndrome is an example of _____ because there is one extra chromosome.

trisomy

DNA

genetic material organized into chromosomes

what does the nucleus contain

DNA

adenine (A) pairs with

thymine (T)

cytosine (C) pairs with

guanine (G)

how many chromosomes does a human have

46

diploid

having two copies of each chromosome

how many chromosomes are in a haploid

23 (gametes)

how many chromosomes do we get from each parent

23

alleles

different forms of the same gene

heterozygous

different alleles

homozygous

same alleles

mutations

changes in DNA

which mutations can be passed on?

the ones that occur in the gametes, like egg and sperm

mitosis

occurs in body cells

starts with a diploid cell and ends with two identical diploid cells

meiosis

occurs in SEX CELLS

starts with a diploid cell and ends with FOUR different haploid cells

spermatogenesis

male body produces mature sperm cells from immature germ cells

oogenesis

process of making female sex cells inside a females ovaries

when a sperm fuses with an egg, what becomes of it?

a zygote

zygote begins to divide as it moves through the uterine tubes to the uterus, what does it become?

morula

what does the morula form into?

forms into a blastocyst

what will the inner cells of the blastocyst become

embyro

what will the outer cells of the blastocyst become

the placenta

what implants on the uterus

blastocyst

what is the role of the placenta

connects to the embyro through the umbilical cord

helps prevent parental blood and baby blood from mixing

how many veins and arteries does the umbilical cord have

ONE vein

TWO arteries

what does the placenta do

produce hCG

progesterone and estrogen, needed to maintain the pregnancy

placental lactogen

what are the three layers of the germ layers

ectoderm, mesoderm, endoderm

ectoderm

nervous system, skin

mesoderm

skeletal, muscular, urinary

endoderm

digestive and respiratory systems, some reproductive

aneuploidies

incorrect number of chromsomes

trisomy

one extra chromosome

ex: down syndrome

monosomy

1 missing chromosome

ex: turner syndrome

tertatogens

anything that can cause damage to the embyro resulting in birth defects

if wolffian ducts develop, which gender will the baby be

male

if mullerian ducts develop, what gender will the baby be?

female