End of unit questions Flashcards
these three organelles are found in cells: the nucleus, the mitochondrion, and chloroplasts. which of the above organelles would be found in:
i. a cell from a human muscle?
ii. a palisade cell from a leaf?
iii. a cell from the root of a plant?
i. nucleus, mitochondrion
ii. nucleus, chloroplast, mitochondrion
iii. nucleus, mitochondrion
explain fully why a cell from the leaf of a plant has chloroplasts but a cell from the root of a plant doesn’t.
the cells in a root have no chloroplasts because they don’t recieve any light and so can’t carry out photosynthesis.
what is the function of each organelle?
Nucleus controls the activities of the cell; chloroplast absorbs light energy for photosynthesis; mitochondrion carries out some of the rections of respiration to release energy.
Explain why an artery can be considered an organ whereas a capilary can’t
The artery is an organ because it is made of several tissues; the capilary is made up of only one type of cell.
what does the digestive system do?
Breaks down large insoluble molecules into smaller soluble molecules that can be absorbed
name 3 organs in the human digestive system. explain what each organ does as a part of the digestive system.
- mouth: chews/breaks down into smaller pieces/produces saliva
- oesophagus: move food from mouth to stomach
- stomach: produces digestive enzymes
- pancreas: produces digestive enzymes
- liver: makes bile
- ileum:produces digestive enzymes/absorbs products of digestion
- colon (large intestine): absorbs excess water
- rectum: stores waste
name 2 other human organ systems, and, for each system, name two organs that are part of the system.
- breathing system: trachea, lung, diaphragm
- circulatory system: artey, vein, heart,
- musculoskeletal system: muscle, joint (named), bone,
- nervous system: brain, spinal cord,
- reproductive system: testis, ovary, uterus, penis
- excretory system: kidney, bladder,
why is it essential that DNA content is doubled before mitosis begins?
so that each of the two cells produced will have the correct number of chromosomes/ correct ammount of DNA after the division.
what is the importance of the small intestine having villi?
they increase the surface area for greater absorption
plants have cell walls made of…
finish the sentence.
cellulose.
Plants store carbohydrate as the isoluble compound called (1)________ or sometimes as the sugar (2)________.
fill in the blanks
(1) starch, (2) sucrose
Plants make these substances (starch and sucrose) as a result of the process called…
finish the sentence
photosynthesis.
Animals store thier carbohydrate as the compound…
finish the sentence
glycogen.
Both animals’ and plants’ cells have nuclei, but the cells of bacteria lack a true nucleus, having thier DNA in a circular chromosome. They sometimes also contain small rings of DNA called ________, which are used in genetic engineering.
fill in the blank
plasmids
Bacteria and fungi break down organic matter in the soil. They are known as…
finish the sentence
decomposers/saprotrophs.
