BIOL 1406 - exam 4 review

Where did HeLa cells come from?

Henrietta Lack

What kind of cancer cells are HeLa cells?

cervical cancer cells

What have HeLa cells been used for?

to develop everything from cloning to the polio vaccine, develop cancer drugs, drugs to treat HIV, herpes, parkinson's disease, and others

What type of cells regenerate the slowest?

reproductive cells

What types of cells regenerate the fastest?

somatic cells

What type of cells do not regenerate at all?

neurons, skeletal muscle, cardiac cells

cytoplasmic division

cytokinesis... the separation of a cell's cytoplasm to form 2 new cells

How can you see that cytoplasmic division is beginning?

the center of the cell is compressed and begins to look like 2 cells

What causes cytoplasmic division?

in animal cells, an expanding cleavage furrow

-in plant cells, an expanding cell plate

cancer

occurs when abnormally dividing cells of a malignant neoplasm disrupt body tissues physically and metabolically

Neoplasm

an accumulation of abnormally dividing cells

Metastasis

the process in which malignant cells migrate and establish neoplasms elsewhere in the body

Tumor

a neoplasm that forms a lump

oncogene

gene that has the potential to transform a normal cell into a tumor cell

Proto-oncogene

gene that can become an oncogene

checkpoint gene

genes that allow problems to be corrected before the cycle advances

How many chromosomes do diploid cells have?

46

How many chromosomes do haploid cells have?

23

asexual reproduction

one parent transmits its genes to offspring - produces clones

What are some of the species that reproduce using asexual reproduction?

yeast, bacteria, insects

homologous chromosomes

have the same size and shape and carry the same genetic information

G1

the first interval (or gap) of cell growth cells engage in their metabolic business

G2

the second interval (or gap) when the cell makes proteins that will drive cell division

S

the time of synthesis (dna replication) when the cell prepares to divide

spindle apparatus

dynamically assembled and disassembled network of microtubules

What does the spindle apparatus do?

moves chromosomes during nuclear division

interphase

the cell grows, doubles the number of its cytoplasmic components, and replicates its dna in preparation for division

Prophase

stage of mitosis during which chromosomes condense and become attached to a newly forming spindle

Metaphase

stage of mitosis at which the cells chromosomes are aligned midway between poles of the spindle

Anaphase

stage of mitosis during which sister chromatids separate and move to opposite spindle poles

Telophase

stage of mitosis during which chromosomes arrive at the spindle poles and decondense, new nuclei form

chromatids

one strand of a double stranded chromosome

Sister chromatids

2 identical chromatids that are attached at a centromere

Meiosis

produces reproductive cells

mitosis

cells replicate themselves to replace old and/or damaged body cells

What happens to the chromosome number during mitosis?

it is maintained

What happens to the chromosome number during meiosis?

it is halved

four stages of mitosis

prophase, metaphase, anaphase, telophase

cytokinesis

the division of a cells cytoplasm

cleavage furrow

in a dividing animal cell, the indentation where cytoplasmic division will occur

What type of skin cancer is most common?

basal cell carcinoma

What type of skin cancer is most deadly?

melanoma

Which skin cancer spreads fastest?

melanoma

What are some ways people can reduce the risk of developing cancer?

not smoking and avoiding exposure of unprotected skin to sunlight can reduce one's risk of acquiring mutations that cause cancer

crossing over

process in which homologous chromosomes exchange corresponding segments during prophase 1 of meiosis

Why is crossing over important?

it produces genetic variation

What's the purpose of sexual reproduction?

genetic variation and gene inheritance from both parents

oogenesis

female production of eggs

polar bodies

germ cells that undergo meiosis and eventually degenerate

What is the final product of oogenesis?

one ovum

fertilization

the joining of a two haploid gametes to form a diploid zygote

zygote

cell formed by fusion of two gametes - the first cell of a new individual

diploid

cells with homologous pairs of chromosomes

Haploid

cells that have one of each chromosome

How does diversity arise in organisms that reproduce asexually?

mutations

What two things contribute to genetic diversity?

independent assortment and crossing over

cell plate

a disk shaped structure that forms a cross wall between two new plant cell nuclei

adaptive trait

a trait that spreads more quickly through a sexually reproducing population than an asexually reproducing one

Why are adaptive traits advantageous?

they enable better survival and reproduction compared with other members of the species

What are some examples of adaptive traits?

flying and camouflage

somatic cells

cells relating to the body

How many chromosomes do somatic cells have?

46

alleles

forms of a gene that encode slightly different versions of the gene's product

germ cells

diploid (immature) reproductive cell that gives rise to haploid gametes by meiosis

gametes

mature haploid reproductive cell that gives rise to haploid gametes by meiosis

How many chromosomes do gametes have?

23

sporophyte

diploid spore producing stage of a plant life cycle

gametophyte

haploid multicelled body in which gametes form during the life cycle of plants

How many sperm are created during meiosis?

4

How many eggs are created during meiosis?

1