BIO EXAM REVIEW Flashcards
Diploid
two complete sets of chromosomes, one from each parent.
what cells are diploid in the body?
Muscle cells
Skin cells
Blood cells
Nerve cells
Bone cells
Haploid
a cell that contains a single set of chromosomes
what cells are haploid in the body?
only egg and sperm cells
how many chromosomes do humans have?
46
Gamete
reproductive cell of a plant or animal
how many chromosomes do gametes have?
23
why do gametes have only 23 chromosomes?
gametes are produced during meiosis, which is a type of cell division that reduces the number of chromosomes in a parent diploid cell by half.
what is fertilization?
the fusion of a haploid male and female gamete to create a diploid cell (zygote)
Somatic cells
any cell in a living organism besides reproductive cells
germ line cell
the cells that form eggs in women and sperm in males
what is mitosis used for?
during mitosis one cell divides to create 2 identical cells, this is for growth and to replace damaged or worn out cells
Stages of mitosis
prophase
metaphase
anaphase
telophase
cytokinesis
what happens in prophase?
condensation of chromosomes
movement of the centrosomes
formation of the mitotic spindle
beginning of nucleoli break down
what happens in metaphase?
mitotic spindle is fully developed
centrosomes are at opposite poles of the cell chromosomes are lined up at the metaphase plate
what happens in anaphase?
sister chromatids will separate and move to opposite poles of the cell, pulled by microtubules
what happens in telophase?
the chromosomes begin to decondense
the spindle breaks down
the nuclear membranes and nucleoli re-form.
what happens in cytokinesis?
splits the parent cell into two identical daughter cells
what is meiosis used for?
allows sexual reproduction of diploid organisms
enables genetic diversity
aids the repair of genetic defects
how does meiosis provide genetic variety?
meiosis creates new combinations of genetic material in each of the four daughter cells
crossing over
the exchange of DNA between paired homologous chromosomes (one from each parent) that occurs during the development of egg and sperm cells (meiosis).
what are homologous pairs?
a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization
what are sister chromatids
two identical chromatids that are formed by replication of a chromosome
what are bivalents/recombinants?
2 sister chromatids
what is monosomy ?
the absence of one member of a pair of chromosomes
ex: if you child was born with only one X chromosome rather than 2 (XX or XY) your baby would have “monosomy X”
what is trisomy?
the presence of an extra chromosome in some or all of the body’s cells
what’s an allele?
the alternative form or versions of a gene
What is the relationship between genes, proteins, and chromosomes?
all subcellular particles
phenotype
the set of observable characteristics or traits of an organism
genotype
the set of genes that it carries
what is an inheritance pattern?
describe how genetic variants are distributed in families
discrete vs continuous inheritance
Continuous may be something like height, which may vary in a population “continuously”, with no specific limitations.
“Discrete” could be choices or outcomes of a small limit of options - there are not gradations or “continuity” between the choices.
incomplete/codominant/dominant inheritance
Incomplete- a dominant allele does not completely mask the effects of a recessive allele
codominant-two different versions of a gene are expressed, and each version makes a slightly different protein
dominant-a way a genetic trait or condition can be passed down from parent to child
autosomal/sex-linked inheritance
Sex-linked inheritance is due to the transmission of sex genes in X and Y chromosomes.
autosomal inheritance is due to the transmission of genes in autosomes or non-sex determining chromosomes.
when you breathe in what muscles contract? what happens to the lung volume?
diaphragm and external intercostals contract, expanding the chest.
the diaphragm flattens and lung volume increases
when you breathe out what muscles contract? what happens to the lung volume?
abdominal and internal intercostals contract causing the lung volume to reduce
4 stages of respiration
- ventilation
- external respiration
- internal respiration
- cellular respiration
Describe three features of alveoli that maximize their function?
1.have a spherical shape to maximize surface area
2. they have tiny blood cells called capillaries
3. they have moist walls that help gas dissolve that help them pass through during gas exchange
What are the two main requirements for gas exchange to occur in the respiratory system of an organism?
- respiratory surface area must be large enough to meet gas exchange requirements
- moist environment because oxygen and carbon dioxide are dissolved in water
Why does the trachea have cartilage rings? Do they go all the way around? Why/why not?
to keep airways open
no, they don’t go all the way around they are “C” shaped because the trachea is too narrow
15 cm log and 2-3 cm in diameter
What is the role of mucus in the respiratory system?
moistens, lubricates, and protects many of the passages of the digestive and respiratory tracts in the body
What structure is shared between the respiratory and digestive system in the throat?
pharynx
Is glucose the same thing as energy? Is it directly usable by cells? Explain.
glucose is our bodys main energy source
no cells cant directly use glucose because the cell might lose energy produced by the oxidizing glucose if all of the energy wasn’t needed immediately.
function of the villi in the small intestine
absorb nutrients from the liquid mixture called chyme produced in the stomach from the food we eat
function of the microvilli in the small intestine
absorb food passing through the small intestine and transfer the nutrients into the blood stream.
What are two features of villi that make them well-suited to their function?
the folded villi greatly increase the surface area of the intestine
2. made of a single layer of thin cells (one cell thick) so there is a short diffusion path
prokaryotic cells
-unicellular micro-organisms
-lack distinct nucleus
-lack membrane-bound organelles
-always bacteria
-simple and small
-reproduction is asexual
eukaryotic cells
-multicellular organelles
-have nucleus
-have membrane-bound organelles
-larger & more complex
-plants/animals/fungi/protists
-never bacteria
-reproduction can be asexual or sexual
Plant Vs. Animal Cells
Plant cells have a cell wall, animals don’t.
Plants have chloroplast, animals don’t.
Plants have one or more large vacuole, animals have multiple smaller ones.
archaea
prokaryotic
no chloroplast
contains a cell wall
mode of nutrition: autotrophic
motility: flagella
unicellular
bacteria
prokaryotic
no chloroplast
contains a cell wall
mode of nutrition: hetero and auto
motility: flagella
unicellular
Protista
eukaryotic
has chloroplasts
some have cell walls
mode of nutrition: auto
motility: flagella
most uni, some multi
fungi
eukaryotic
no chloroplast
contains a cell wall
mode of nutrition: hetero
motility: non motile
multicellular
plantae
eukaryotic
chloroplast
contains a cell wall
mode of nutrition: auto (phtosynthesis)
non motile
multicellular
Animalia
eukaryotic
no cell wall
no chloroplast
mode of nutrition: heterotrophic
motile
multicellular
autotrophic mode of nutrition
take in substances from outside and convert them into stored forms of energy
heterotrophic mode of nutrition
where the organism is unable to prepare its food and hence, depends upon plants or other organisms for nutrition
stages of the cell cycle
G1
S
G2
M
G1
the cell grows physically and increases the volume of both protein and organelles
S phase
the cell synthesizes a complete copy of the DNA in its nucleus
G2
The Cell “double checks” the duplicated chromosomes for error, making any needed repair.
mitosis
one parent cell physically divides into two daughter cells.
