Biology 9 Flashcards
What is cell theory
Who are the 3 discoverers of cell theory?
The basic principles of biology
Theodor Schwann, Matthias Schleiden, Rudolph Virchow
What can cells be
Unicellular or multicellular
Red blood cells have no nucleus
True
Most important function of a cell
Produce proteins
What are proteins and what are they made up of
Biological molecules, made up of amino acids
Examples of amino acids
Hemoglobin, insulin, keratin, collagen, enzymes
How do you calculate field of view
Low power f.o.v x magnification of low power / magnification of medium power
Nucleus
Most visible component of a cell (controls everything
Nuclear membrane
A barrier to what can eneter/exit
Nuclear pores
Allows ribosomes and RNA to exit the nucleus
Chromatin
Material inside the nucleus that’s composed of unraveled chromosomes containing DNA
Nucleolus
Visible part, responsible for production of ribosomes to be transported outside the nucleus to the rough ER
DNA
Deoxyribonucleic acid
Blue print for the body
Nucleotides
Basic unit of DNA
What are nucleotides made up of
One sugar and phosphate molecule and one of the four nitrogen bases
4 nitrogen bases
Adenine, thymine, cytosine, guanine
A-T, C-G
Nucleotide diagram
Rectangle (phosphate) - house (sugar) - circle (base)
Double helix
Double stranded molecule (twisted ladder)
Covalent bonds
Hold atoms together
Hydrogen bonds
Hold two strands of the spiral together (weak)
Genes
Segment of DNA that codes for a protein (determined by bases)
Responsible for all characteristics
Genome
Organisms genes
Human genome is contained in the….
23 chromosomes in the nucleus
DNA Replication (Steps)
Unwind - base pairing - joining
DNA Replication
DNA unzips when it splits- if you know the bases of one strand then you know the other
DNA replication enzymes
Polymerase- helps new bases join old
Helicase- separates DNA
Genes store all the information needed to produce how many proteins
10,000 to 90,000
RNA
Ribonucleic acids
Single stranger
What sugar does RNA contain
Ribose
3 types of RNA
mRNA, tRNA, rRNA
Four base pairs of RNA
Adenine, cytosine, guanine, Uracil
A-U, C-G
Chromosomes
Made up of one strand of DNA, two chromatids paired
Chromatid
A copy of the chromosome after it has replicated
Centromere
The regions where chromatids are attached
What do chromosomes determine
Sex of a person (M = Y, F= X)
What are each chromosomes paired with
Another chromosome that has the same genetic information
Cell division: functions
Growth, repair, reproduction
What happens in the growth phase of cell division
Organisms begin as a single cell (multicellular cells go through cell division to increase)
Cytoplasm increases
Cells specialize and grow tissues/organs when a body gets enough cells
What happens in the repair phase of cell division
Multicellular cells can become damaged
What happens in the reproduction phase of cell division
Unicellular cells use cell division
Single celled bacteria reproduce (identical copies)
Cell cycle phases
Interphase, mitosis, cytokinesis
What happens in interphase
Growth phase
Cells synthesize proteins
DNA copies itself
Four phases of interphase
G0: cells are always resting
G1: Growth in cell
S: DNA replication
G2: Further growth
What happens in mitosis
Nucleus division
DNA movement is caused by spindle fibers
What happens in cytokinesis
Cell divides
Daughter cells
4 phases of mitosis
Prophase
Metaphase
Anaphase
Telophase
What happens in prophase
First stage- chromosomes “coil”, nuclear membrane disappears, centrioles divide and move to opposite poles
What happens in metaphase
Chromosomes line up and spindle fibers pull them apart
What happens in anaphase
Centromeres split, sister chromatids move apart
What happens in telophase
Chromosomes reach opposite poles, nuclear membrane reforms; cytokinesis begins
Asexual reproduction
One parent, genetically identical, cells are not specialized for reproduction (no sperm/eggs)
Binary fission
An organism that splits into two equal halves, a method of reproduction for bacteria and protists (unicellular eukaryote, ex. Euglena)
Budding
A growth on the parent cell and when developed enough breaks off
Spore formation
Organisms form a special cell (spore) which is released into any environment where it can grow
Ex. moulds
Fragmentation
Breaking off part of the parent
Vegetative propagation
Only in plants- they grow a long stem which is called a runner which breaks off
Genetic diversity
The result of sexual reproduction which shuffles DNA
Variation
The genetic differences in a species
Gametes
Sex cells (sperm and egg) Three stages: production of gametes, fertilization, development
Autosomes
Not responsible for determining sex
Sex chromosomes
Determine the sex
XY = M
XX = F
Homologous chromosomes
Same size, similar genes on same location, gene for colour, etc.
Diploid cell
2 sets of chromosomes (nerve, skin, muscles, STEM)
Haploid cell
1 set of chromosomes (egg and sperm)
How many homologous chromosomes do males and females have
F = 23 M = 22 because the sex chromosomes X and Y are not homologous
Meiosis
The process where haploid gametes are made in the body (ovary of female, testes of males) - gonads
What are the two sets of division for meiosis
Meiosis I and meiosis II
How does meiosis work
Basically the same as mitosis in terms of phases, but instead of resulting in two identical daughter cells, it results in four sex cells
3 stages of reproduction
Mating, fertilization, embryonic development
Fertilization
Process where eggs and sperm combine
Cell division will only occur if
Enough nutrients, warm enough temperature, sufficient moisture, good protection
Two types of fertilization
Internal and external
Zygote
Fertilized egg
Morula
When the zygote divides several times to form a cluster of cells
Blastula
When the cells organize themselves into 3 layers
Gastrula
Differentiation- The cell layers form organs and tissues
Placenta
When the embryo forms finger-like projectiles of villi into the uterus lining
Provides nutrients and oxygen
First trimester
Brain, spinal cord, ears, eyes, organs, sexual differentiation
Second trimester
Movement, open eyelids, fetus can survive outside w/ special care
Third trimester
Rapid weight gain
Reproduction hormones
Testosterone and estrogen
Testes
Where sperm is made, makes male hormone
Scrotum
Sac-like organ containing the testes; outside body to montior temp
Seminiferous tubules
Tubes that make up the testes; where sperm is made
Epididymis
Organ where sperm are stored
Vas deferens
Help transport sperm
Ejaculation
How sperm is released
Semen
Seminal vesical and prostate add this fluid to sperm
Erectile tissue
A specialized tissue where blood flows to enable erection
Ovaries
Female gametes where eggs are stored and mature
Estrogen, progesterone
Hormones that regulate periods
Uterus
Nourishes fetus
Fallopian tubes
Fertilization happens here
Cervix
Neck of uterus (ring of muscles)
Vagina
A tube that the cervix leads to
Vulva
External genetilla
Oviduct
Fallopian tubes (where egg travels)
Clitoris
Sensitive part above uretha
LH, FSH
Hormones
LH = Ovulation
FSH = Stimulates follicles to develop
Menstruation
When the lining of the uterus breaks down
Follicle
A fluid filled ball developing in the ovary containing an egg, eventually bursting which releases the egg into the oviduct (ovulation)
After ovulation the egg develops in a thick lining of blood and glands
Ovulation
When the follicle bursts and releases an egg into the oviduct
If fertilization occurs, the egg implants in the uterus resulting in pregnancy
If no fertilization occurs, the period continues
Yellow body
A follicle that remains after the egg is released, and also breaks down in the uterus
Plan gametes
Egg cells Pollen grains (M)
Angiosperms
Flowering plant reproductive structure
Plants
Moss, ferns, etc.
Flowers are…
the reproductive system (seeds grow, plant)
Seed
When pollen grains fertilize the egg cell
Sepals
Small leaves, protect bud
Petals
Scented/colored (usually), produce sugary nectar from the base
Stamens
Male sex organs
Anther: Where pollen is made
Filament: Stalk holding the anther
Carpels/Pistil
Female sex organs
Stigma, style, ovary
Pollination
Transfer of pollen from anther to carpel
Where do pollen grains land on during pollination
Stigma
What does the style join to the ovary
The stigma
Self pollination
When pollen from the anthers of one flower lands on the stigma of the same flower
Cross pollination
When pollen from the anthers of a flower lands on the stigma of a flower of the same species (more variation)
Insect pollination
Pollen is distributed by insects
Colorful, scented petals to attract, anthers/stigmas inside for insects to rub against, small amounts of sticky pollen for the ability to stick to insects bodies
Wind pollination
Pollen is distributed by wind
Anthers hang outside to catch wind, large, feathery stigma’s to catch pollen grains in the air, smooth, light pollen is made so it can be easily transported by the wind