#Question id: 5661
#Unit 5. Developmental Biology
Following statements regarding to the embryogenesis in A. thaliana.
A. The first zygotic division is unequal, with the basal cell larger than the apical cell. The basal cell divides to give rise to the suspensor. The apical cell divides vertically to form a two-celled proembryo, which will give rise to the rest of the embryo.
B. The top most suspensor cell is recruited into the embryo, where it is known as the hypophysis, and contributes to the embryonic root meristem and root cap.
C. The next two divisions produce an eight-cell octant-stage embryo, which develops into a heart-stage embryo of around 32 cells
D. The embryo elongates and the cotyledons start to develop as wing-like structures at one end, while an embryonic root forms at the other. This stage is known as the globular stage.
Which of the following statements are correct?
#Question id: 24643
#Unit 10. Ecological Principles
Which of the following statements about typical soil horizons is correct?
#Question id: 2300
#Unit 2. Cellular Organization
Which of the following is not found in cell sap?
#Question id: 29542
#Unit 6. System Physiology – Plant
R gene products are also called as
#Question id: 4973
#Unit 11. Evolution and Behavior
Fossils of Lystrosaurus, a dicynodont therapsid, are most common in parts of modern-day South America, South Africa, Madagascar, India, South Australia, and Antarctica. It apparently lived in arid regions, and was mostly herbivorous. It originated during the mid-Permian period, survived the Permian extinction, and dwindled by the late Triassic, though there is evidence of a relict population in Australia during the Cretaceous. The dicynodonts had two large tusks, extending down from their upper jaws; the tusks were not used for food gathering, and in some species were limited to males. Food was gathered using an otherwise toothless beak. Judging from the fossil record, these pig-sized organisms were the most common mammal-like reptiles of the Permian.Which of Lystrosaurusʹ features help explain why these organisms fossilized so abundantly?
I. the presence of hard parts, such as tusks
II. its herbivorous diet
III. its persistence across at least two geological eras
IV. its widespread geographic distribution
V. its mixture of reptilian and mammalian features