Bio 2 Ch. 19 & 21

Study Guide Q - How many genes are in the human genome?

22,000 - 25,000 genes

Ch. 21 - According to your book wen does aging begin?

40 years old

Ch. 19 - Cystic fibrosis is a genetic disorder that results from the inheritance of 2 recessive alleles. What is the chance that a child will inherit the disorder if one parent is heterozygous for this gene and one parent has cystic fibrosis?

50%

Ch. 19 - There is a male dog has black fur represented as [B], and is homozygous dominant. There is also a female dog with white fur represented as [b], and is heterozygous. What are the genotypes of the offspring?

50% BB and 50% Bb

Study Guide Q - A couple gives birth to 4 girls in a row. What are the chances that the next born will be a boy?

50% girl and 50% boy

Study Guide Q - Approximately what is the human life span in America today?

77 years old

Ch. 19 - There is a male dog has black fur represented as [B], and is homozygous dominant. There is also a female dog with white fur represented as [b], and is heterozygous. What are the phenotypes of the offspring?

All black

Study Guide Q - Embryonic membranes and what they do

Amnion: filled with amniotic fluid & absorbs physical shocks & keeps baby from drying out Allantois: helps form umbilical chord & blood vessels that connect baby to placenta Yolk Sac: hangs from baby's belly & produces blood cells, source of cells that will become sex cells Chorion: outermost layer that produces HCG, which shows up on a pregnancy test

Study Guide Q - Relations ship between chromosomes, alleles, genes, and traits

Chromosome: genetic info in nucleus Allele: alternative version or form of a gene A gene: serves instructions for making different proteins A trait: genes code for proteins that are expressed as traits

Study Guide Q - What's the difference between a dominant and a recessive allele?

Dominant alleles determine appearance and recessive alleles usually have no effect on appearance

Study Guide Q - Developmental stages

Embryo: conception - 2 months Fetus: 2 months - birth Neonate: first month outside of mom Child: 16 months - 12 years Adult: Beyond 20 years old

Study Guide Q - What are the 3 germ layers from the inside out

Endoderm (inside), Mesoderm (middle), and Ectoderm (outside)

Study Guide Q - What are the female and male sex chromosome combinations (genotypes)

Female: "XX" is the fairer sex Male: "XY" makes a guy

Study Guide Q - What is colostrum and what is it "rich" in?

First form of milk produced by the mammary glands, and its rich in antibodies, also known as passive immunity

Study Guide Q - Where does fertilization take place?

In the ovary

Ch. 21 - This hormone is responsible for both milk let down as well and the uterine contractions during delivery.

Oxytocin

Ch. 21 - This hormone is responsible for milk production in the mammary glands.

Prolactin

Study Guide Q - What are telomeres?

Short terminal segments or tips of chromosomes that are removed each time a cell is replicated

Study Guide Q - What is milk composed of?

Sugars, fats, proteins, and water

Ch. 19 - People with Down syndrome have a genotypic condition identified as what?

Trisomy 21

Study Guide Q - What is codominant and know why A and B blood types are codominant.

When both alleles are expressed equally. Blood type O is recessive and blood types A&B are codominant cuz they're expressed equally

Study Guide Q - Definition of incomplete dominance and an example

When the heterozygous genotype results in a phenotype that is intermediate between the 2 homozygous phenotypes of the parents. Ex: Wavy hair

Study Guide Q - Basics of Turner Syndrome

XO (only occurs in women)

Ch. 19 - Which of the following genotypes results in the female gender?

XX

Study Guide Q - Basics of Klinefelter Syndrome

XXY (only occurs in males)

Study Guide Q - What is a zygote and how many chromosomes does a human zygote contain?

Zygote = fusion of sperm and egg, and it has 46 chromosomes

Ch. 21 - Beginning at 2 months up until birth you are considered what?

a fetus

Study Guide Q - What is a karyotype?

a numbered arrangement of all 23 pairs of human chromosomes

Study Guide Q - Identical twins

a zygote splits in half and both zygotes go into the uterus separately with their own placenta. They're genetically identical to one another

Ch. 21 - Which of the following embryonic membranes is a temporary membrane that helps form the blood vessels of the umbilical cord?

allantois

Ch. 21 - From essentially conception to two development in utero you are considered ________.

an embryo

Ch. 19 - Imagine this hypothetical situation. A pure black colored dog is crossed with a pure white colored dog and all the puppies come out black. This would be an example of which of the following situations?

classic dominant and recessive interactions

Ch. 19 - Imagine this hypothetical situation. A pure black colored dog is crossed with a pure white colored dog and all the puppies come out with black and white stripes like a zebra. This would be an example of what situation?

codominance

Ch. 21 - During the first day or so after birth, the breasts produce a water milk which is rich in antibodies. This first milk is called what?

colostrum

Ch. 21 - The placenta forms from embryonic tissue and what?

endometrium

Ch. 19 - If both alleles of a particular gene are identical such as (AA or aa); the person is said to be what?

homozygous

Ch. 19 - An example of a genotype would be what?

homozygous dominant

Ch. 21 - This hormone is a signal that a women is pregnant.

human chorionic gonadotropin (hCG)

Ch. 21 - The structures zona pellucida and corona radiata can be associated with the what?

human egg

Ch. 21 - Research on the aging process shows that wounds of the elderly heal more slowly and that they are more susceptible to disease. These are problems associated with an aging _______ system.

immune

Ch. 19 - Imagine this hypothetical situation A pure black colored dog is crossed with a pure white colored dog and all the puppies come out grey. This would be an example of what situation?

incomplete dominance

Study Guide Q - What is polygenic inheritance and an example

inheritance of phenotypic traits that depend on many genes. Ex: Eye color & height

Ch. 19 - Which one of the following is true regarding an individual who has inherited one sickle cell gene and one normal gene for hemoglobin?

is less likely to contracting malaria

Ch. 21 - Which of the following organs is NOT fully developed in a fetus and is therefore bypassed by the ductus arterisus?

lungs

Ch. 21 - What part of the sperm contains the most mitochondria for generating ATP?

midpiece (B on model shown)

Ch. 21 - The first 3 days or so of human embryonic development occur in the what?

oviduct

Ch. 19 - The Punnett square is a useful tool for what?

predicting the potential genotypes of offspring based on the known genotypes of the parents

Ch. 21 - Maturation of the reproductive organs and the reproductive response is called what?

puberty

Ch. 21 - To penetrate the zona pellucida of the egg cell the sperm?

releases digestive enzymes from the acrosomal cap

Study Guide Q - What are genotypes?

set of alleles that an individual possesses

Ch. 21 - Which of the following is NOT true regarding telomeres and telomerase?

the number of telomeres increases with every cell division

Study Guide Q - What are phenotypes?

the traits that an individual exhibits

Ch. 19 - Assume tall [T] is dominant to dwarf [t]. If a homozygous dominant individual is crossed with a homozygous dwarf, the offspring will be what?

they'll all be tall

Ch. 19 - What is the significance of crossing-over during prophase 1 of meiosis?

to increase the genetic variation of gametes and offspring

Study Guide Q - Basics of Down Syndrome

trisomy 21 (trisomy of chromosome set 21, 3 chromosomes instead of 2)

Study Guide Q - Fraternal twins

when 2 eggs are ovulated and fertilized by 2 different sperm

Ch. 21 - When does a zygote form?

when the nucleus from the sperm fuses with the egg nucleus