Midterm Study guide
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Midterm Study guide
Science Midterm Study Guide
What are the products of photosynthesis?
oxygen & sugar
What happens during photosynthesis?
plants and some other organisms use energy from the sun to convert
carbon dioxide & water into oxygen & sugar
How does photosynthesis benefit heterotrophs?
makes food for them to eat
What happens during respiration?
cells break down simple food molecules such as sugar and glucose
and release the energy they contain
The stage of respiration that releases most of the energy in glucose
occurs in the
How are photosynthesis and respiration related?
same formulas just opposite
Together, respiration and photosynthesis keep the levels of carbon
dioxide and oxygen in the atmosphere
The energy-releasing process that does not require oxygen is
When is lactic-acid fermentation most likely to occur?
running fast or exercising
Explain the process of Mitosis. Know all stages and what occurs in
Prophase – Chromatin in the nucleus condenses to form chromosomes. The parts of centrioles move to opposite
sides of the nucleus. Spindle fibers form a bridge between the ends of the
Metaphase – The chromosome line up across the center of the cell. Each chromosome
attaches to a spindle fiber at its centromere.
Anaphase – The centromeres split. The 2 chromatids separate. One chromatid is drawn by
its spindle fiber to one end of the cell. The other chromatid moves to the
opposite end. The cell stretches out as the opposite ends are pushed apart.
Telophase – The chromosomes begin to stretch out and lose their rodlike appearance. A new
nuclear envelope forms around each region of chromosomes.
cell’s nucleus divides into 2 new nucleus – remember cell cycle (the word)
What happens during cytokinesis in animal cells?
the cell membrane squeezes together around the middle of the cell. The
cytoplasm pinches into 2 cells. Each daughter cell gets about half of
Explain the DNA molecule. What shape is it? What are the nitrogen
base pairs and how do they pair up with each other?
twisted ladder or spiral stair case. Adenine(A)-Thymine(T) Cytosine(C)-Guanine(G)
What captures energy from sunlight during photosynthesis?
stomata-Co2 collector Chloraphyll-pigments
Where does alcoholic fermentation occur?
yeast – single celled organisms
What are chromatids?
each identical rod in a chromosome –
identical strands of chromosomes
What forms around the chromatids during mitosis?
2 new nuclei form around the chromatid
All organic compounds contain the element
Why is water important for a cell?
water helps keep their size and shape. It helps keep the temperature from changing rapidly
the movement of materials through a cell membrane using energy
the process by which molecules move from an area of higher concentration
to an area of lower concentration
the movement of dissolved materials through a cell membrane without using cellular energy
Why are enzymes important?
without enzymes, many chemical reactions that are necessary for life would either take too long or not occur at all
What are startches? Lipids?
1. carbohydrate; many foods made of plants contain this
2. energy-rich organic compounds made of carbon, hydrogen, and oxygen
when 2 or more elements combine chemically
What did Gregor Mendel do to study different characteristics in his
crossed pea plants – crossed purebred tall pea plants with purebred
short pea plants
Explain Mendel’s experiment in detail. P generation, F1 Generation, F2 generation.
1. parent generation. He crossed T with t T-tall t-short
2. the offspring form the T and t cross. All the offsprings were tall. TT
3. the plants were a mix of tall and short. the shortness trait has reappeared. ¾ of
the plants were tall and ¼ were short. TTTt
the factors that control a trait
offspring of many generations that have been the same trait
an allele that is hidden when the dominant allele is present
each different form of a characteristic
2 different alleles for a trait
a # that describes how likely it is that an event will occur
a chart that shows all the possible combinations of alleles that can
result from a genetic cross
genetic makeup, allele combinations
physical appearance, visible traits
a condition in which neither of 2 alleles of a gene is dominant or
a change in a gene or chromosome
different form of a gene
TT or tt
What does the notation TT, Tt, tt, mean to geneticists?
TT – dominant homo Tt – dominant
hetero tt – recessive homo
What is the probability of producing a tall pea plant from a
genetic cross between two hybrid tall pea plants?
¾ or 75%
If a homozygous black guinea pig (BB) is crossed with a
homozygous white guinea pig (bb), what is the probability that an
offspring will have black fur?
What is the chromosome theory of inheritance?
genes are carried from parents to offspring on chromosomes
What did Walter Sutton do?
discover Theory of Inheritance. grasshoppers – sex cells, half the
# of chromosomes in body cells